Calculating molarity using solute moles

Question

A chemist prepares a solution of barium acetate BaCH3CO22 by measuring out 117.μmol of barium acetate into a 150.mL volumetric flask and filling the flask to the mark with water.

Calculate the concentration in m/molL of the chemist's barium acetate solution. Be sure your answer has the correct number of significant digits.

Answer 1

As in your previous question, the answer should have 3 significant digits.

Assuming you meant mmol / L….

Find number of mmoles:

117 umols x 1 mmol /1000 umols = 0.117 mmols

Find number of liters:

150 ml x 1L / 1000 ml = 0.150 L

Concentration = 0.117 mmols / 0.150 L = 0.780 mmol / L